FIGURE 1. Three-panel composite image from dose histogram displays module of 3D-ID. (A) Transverse slice of mouse MR image with contours shown for spleen (green), right kidney (yellow), left kidney (red), and liver (orange). (B and C) Corresponding transverse slices from ß-dose distribution images of ¹³¹I and ⁹⁰Y, respectively. Also shown in panels B and C are isodose curves at 1%, 5%, 50%, and 90% levels. Bulge in 1% isodose level shows effect from 0.5-mm-distant portions of spleen. However, as seen in ¹³¹I image, even 1% level does not irradiate nearest organ (left kidney) compared with ⁹⁰Y image, which shows significant portion of left kidney receiving dose from spleen at 1% isodose level.